Friday, December 13, 2013

Some Things Float ~ Some Things Don't

Last week we were testing how well glitter fell through water, and it got me thinking about all the "bathtub science" my kids used to do. You know: toss an apple into a bathtub full of water and it bobs on the surface. But toss in a quarter and it sinks - which makes anyone sitting in the bathtub wonder: how can a huge ship float if it's made of metal?

It's not just the material of an object - or its size - that determines "floatability". Shape has something to do with it as well, and Adler shows how.

Take a piece of aluminum foil. If you put it on top of water, it will float. It will float even if you crumple it a bit into a loose ball. But if you smoosh it into a tight ball it sinks. So it's not weight that matters - because it's the same amount of foil. It's how much space it takes up - its density. Adler explains density, and demonstrates why even "heavy" clay boats can float. He shows what displacement is all about and offers lots of opportunities for kids - and parents - to ask questions and test household objects. All you need is a bathtub. Or a dish pan or a wading pool or a large mixing bowl...

Today's review is part of the STEM Friday blog. Check out the other science books and resources reviewed this week.Review copy provided by the publisher.

1 comment:

Thanks for sharing this book! I've done sink/float with fourth graders and they are still fascinated by it--many of them don't seem to have had these experiences at home. They especially enjoy it when I break out the pumice stone. :)